From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755601Ab0A1PpH (ORCPT ); Thu, 28 Jan 2010 10:45:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755463Ab0A1PpG (ORCPT ); Thu, 28 Jan 2010 10:45:06 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35491 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752714Ab0A1PpD (ORCPT ); Thu, 28 Jan 2010 10:45:03 -0500 Date: Thu, 28 Jan 2010 10:44:48 -0500 From: Don Zickus To: Peter Zijlstra Cc: mingo@elte.hu, gorcunov@gmail.com, aris@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/3] [RFC] nmi_watchdog: config option to enable new nmi_watchdog Message-ID: <20100128154448.GV4472@redhat.com> References: <1264622622-5778-1-git-send-email-dzickus@redhat.com> <1264622622-5778-4-git-send-email-dzickus@redhat.com> <1264690494.4283.2103.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1264690494.4283.2103.camel@laptop> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 28, 2010 at 03:54:54PM +0100, Peter Zijlstra wrote: > On Wed, 2010-01-27 at 15:03 -0500, Don Zickus wrote: > > These are the bits that enable the new nmi_watchdog and safely isolate the > > old nmi_watchdog. Only one or the other can run, not both at the same > > time. > > perf disables the lapic watchdog when it wants the pmu, so there > shouldn't be a problem having both built in. Yes it does disable but does not prevent nmi_watchdog_tick from running nor the /proc interface from being loaded. So perhaps my description isn't very good. The idea with the new watchdog was to re-use some of the bits of the old one, but having them both compiled in seemed to stomp on each other. That is what I was trying to prevent. I can certainly change the behaviour, just makes the code a little more messy I think. Cheers, Don